PEV,where does the heating system heat source come from?
In the cold winter, when sitting in the car blowing warm wind, we have not thought, warm wind heat source is from where?
The answer is: most of the car heating source is from the engine coolant, of course, there are individual cars using resistance wire heating, and a small number of buses and trucks using a separate diesel heater. We all know that when an engine starts to run, it needs to burn gasoline, but not all of that combustion energy is converted into mechanical energy, and a lot of it is taken away by the coolant and the exhaust system, the heat of the car's heating system comes from these waste heat.
But, new energy vehicle has no engine, so where does the warm air heat source of electric vehicle come from?
Today we will introduce the new energy vehicle heating system
New Energy Heating System
When you think of electric cars, it may be easy for you to think of a heater system that directly heats the air with a resistance wire, which is perfectly fine in theory, but there are almost no resistance wire heaters for electric cars, the reason is that the resistance wire consumes too much electricity.
At present, the category of new energy heating system is mainly two categories, one is PTC heating, one is heat pump technology, and PTC heating is divided into air PTC and antifreeze PTC.
PTC heater
PTC thermistor heating system heating principle is relatively simple, and more easy to understand, and resistance wire heating system similar, are by current through resistance heat, the only difference is the resistance material. The resistance wire is made of ordinary metal wire with high resistance value, while PTC used in pure electric vehicle is a kind of semiconductor thermistor. PTC is short for Positive Temperature Coefficient, its characteristic is that the resistance value of PTC material will increase with the increase of temperature. This characteristic determines that under the condition of constant voltage, the PTC heater will heat quickly when the temperature is low, and then the resistance value will increase and the electric current will decrease when the temperature is high, pTC uses less energy, which keeps the temperature relatively constant and saves electricity compared to pure resistance wire heating.
It is these advantages of PTC, now has been all-electric vehicles (especially low-end models) widely used.
And PTC heating is divided into PTC water heating and PTC air heating.
PTC water heating and motor cooling water road together, electric vehicles in the course of running along with the motor operation, the motor will also heat, so in the course of driving heating system can use part of the motor to warm up, and save some electricity. Here is a water heating PTC.
When the PTC heated the coolant, it would flow through the heater core in the cab. Then, it would be similar to the heater system in the fuel truck. Under the action of the blower, the air in the cab would be circulated for heating.
Air-heated PTC is to install PTC directly at the heating core of the cab, circulate the air in the car through the blower and directly heat the air in the cab through the PTC heater. The structure is relatively simple, however, compared to water heating PTC to waste electricity.
Heat Pump Warm Air System
The function of heat pump is to transfer heat energy from low-temperature heat source to high-temperature heat source. When air-conditioning is used to cool, it transfers heat from the inside to the outside, while the heat pump system transfers heat from the outside to the inside of the car, just like putting an air-conditioner outside the cab and an air-conditioner outside the cab. Heat pump heating systems are generally integrated with air conditioning and refrigeration systems, through the valve control of heat transfer path. In addition, when heating, can effectively use the power battery cooling system of preheating. In this respect, similar to the traditional car heating system.
Compared with PTC heater, heat pump system has higher thermal efficiency, lower energy consumption and less impact on range. But the disadvantages are also obvious: complex structure, high cost, slow heating speed, especially in low temperature conditions, heating effect is poor.
Based on the above, in some high-end pure electric vehicles, in order to ensure the temperature of the compartment, often using heat pump + PTC hybrid mode. In the initial stage, because the power battery cooling system temperature is low, start the PTC heater, wait for the coolant temperature rise, then start the heat pump heating system. So smarter heat pumps and PTC-coupled technologies are born.
